What kind of battery does the decoy use: It uses a re-chargeable battery with USB output

How much does the decoy cost: They are not for sale currently

Do I have to connect to the internet: No, the decoy can be programmed to simply start moving when powered on. The only thing is that you lose control by not being connected. It still works, but you can’t push a button on your phone and make it move. It will move on timed cycles

What decoy shells can be used: I’ve used a Montana Decoy "Miss Purrfect" shell in this implementation but any flexible decoy shell can potentially be used